Big delay but probably it is still actual.
I check the dual path using the following:

after lin_tape configuratiin you can see the similar output:

Changer output: 

# cat /proc/scsi/IBM*
lin_tape version: 3.0.6
lin_tape major number: 242
Attached Changer Devices:
Number  model       SN                HBA             SCSI            FO Path
0       03584L32    0000000000000000  qla2xxx         3:0:0:1         Primary
1       03584L32    0000000000000000  qla2xxx         4:0:0:1         Alternate
2       03584L32    0000000000000000  qla2xxx         4:0:3:1         Alternate
3       03584L32    0000000000000000  qla2xxx         4:0:2:1         Alternate

Drives output:

lin_tape version: 3.0.6
lin_tape major number: 242
Attached Tape Devices:
Number  model       SN                HBA             SCSI            FO Path
0       ULT3580-TD6 0000000001        qla2xxx         3:0:0:0         Primary
1       ULT3580-TD6 0000000002        qla2xxx         4:0:0:0         Alternate
2       ULT3580-TD6 0000000003        qla2xxx         3:0:1:0         Primary
3       ULT3580-TD6 0000000004        qla2xxx         4:0:1:0         Alternate

Device name after persistant name configuration done:

[root@rack17s2 atape]# ls -la  /dev/tape/*
lrwxrwxrwx. 1 root root 11 XXX XX 00:14 /dev/tape/rmt_0000000001 -> ../IBMtape4
lrwxrwxrwx. 1 root root 11 XXX XX 00:14 /dev/tape/rmt_0000000003 -> ../IBMtape7
lrwxrwxrwx. 1 root root 14 XXX XX 00:14 /dev/tape/smc0 -> ../IBMchanger0

If you run ITDT you can check and confirm that dual path is configured and 
probably working:

# ./itdt -f /dev/tape/rmt_0000000001 qrypath
Querying SCSI paths...
Total paths configured........... 2

Primary Path Number 1
  Logical Device................. IBMtape4
  Host Bus Adapter............... qla2xxx
  SCSI Host ID................... 3
  SCSI Channel................... 0
  Target ID...................... 0
  Logical Unit................... 0
  Path Enabled................... Yes
  Path Manually Disabled......... No

Alternate Path Number 2
  Logical Device................. IBMtape7
  Host Bus Adapter............... qla2xxx
  SCSI Host ID................... 4
  SCSI Channel................... 0
  Target ID...................... 1
  Logical Unit................... 0
  Path Enabled................... Yes
  Path Manually Disabled……… No


Efim


> 29 апр. 2016 г., в 20:15, Lee, Gary <glee AT BSU DOT EDU> написал(а):
> 
> If I have data path failover support enabled in the lin_tape driver, how do I 
> define the path correctly to tsm?
> 
> I need to make sure I catch the correct /dev/xxxx entry so that lin_tape can 
> manage the data paths.
> What do I use in the device field of the path definition for a drive?